Unified address translation for virtualization of input/output devices

Abstract

Embodiments of apparatuses, methods, and systems for unified address translation for virtualization of input/output devices are described. In an embodiment, an apparatus includes first circuitry to use at least an identifier of a device to locate a context entry and second circuitry to use at least a process address space identifier (PASID) to locate a PASID-entry. The context entry is to include at least one of a page-table pointer to a page-table translation structure and a PASID. The PASID-entry is to include at least one of a first-level page-table pointer to a first-level translation structure and a second-level page-table pointer to a second-level translation structure. The PASID is to be supplied by the device. At least one of the apparatus, the context entry, and the PASID entry is to include one or more control fields to indicate whether the first-level page-table pointer or the second-level page-table pointer is to be used.

What is claimed is: 
     
       1. A method comprising:
 creating, for a virtual machine (VM) by a virtual machine monitor (VMM), a virtual input/output memory management unit (IOMMU) corresponding to a physical IOMMU, the virtual IOMMU having a process address space identifier (PASID) entry width that is smaller than the PASID entry width of the physical IOMMU; and 
 shadowing, by the VMM, a guest PASID from the virtual IOMMU in the physical IOMMU. 
 
     
     
       2. The method of  claim 1 , further comprising configuring, by the VMM, a host PASID in the physical IOMMU PASID table, the host PASID corresponding to the guest PASID. 
     
     
       3. The method of  claim 2 , wherein the guest PASID is to be used by a virtual function or a physical function of an input/output device assigned to the VM. 
     
     
       4. The method of  claim 2 , wherein the host PASID is to be used by an assignable interface (AI) of an input/output device assigned to the VM.